Switched from BT and sync speed dropped significantly

Hi, I was a BT customer for two years during which time I learnt that the Openreach infrastructure in my area is poor (although no engineer could give me a definitive reason; aluminium cables, full cabinets and crosstalk were all mentioned). The upshot of this is that I never got a download sync speed better that about 25mb and the connection could be quite unstable at times.

I left BT when they hiked their prices and my sync speed was drifting down. It was about 18mbps when I left a couple of weeks ago. At first the switch to plusnet went exactly as expected: the speed was the same but I was paying less. Then suddenly the speed dropped down to 5mbps and stayed there. It keeps dropping the connection but every time it reconnects around 4-6mbps. It almost looks as if I've been throttled as the modem can still 'see' the maximum speed of my line (see attachment).

I've also attached Openreach's expectation for my line from a while ago. For some reason the BT Wholesale test is crashing currently... maybe related to my issue?

Re: Switched from BT and sync speed dropped significantly

Yes and the results are mixed. Most of the time it's normal with perhaps low levels of intermittent crackling, but sometimes there are loud bursts of noise which can go on for some time. This isn't a new development though, the line is poor and Openreach seem unwilling to improve it. What's new is that some kind of additional restriction seems to have been applied beyond the 'natural' restriction of the line quality. Also, with this latest drop in speed my ping has gone from 9ms to about 50ms which is making for a poor browsing experience.

Re: Switched from BT and sync speed dropped significantly

PlusNet have NO control over the sync speed, it's purely down to the BT Openreach DLM in the cabinet. If the phone line has noise then that will likely be affecting the sync speed. You need to report the noisy line fault and get that fixed.

Re: Switched from BT and sync speed dropped significantly

Hi, none of this helped unfortunately and now my ping has shot up to 997ms! I'm bewildered as I knew my line was bad and I'm not expecting you to fix that but some kind of additional external restriction seems to have occurred since I switched to plusnet...

Re: Switched from BT and sync speed dropped significantly

The firewall on the router seems very busy considering I'm not running anything that I would expect to need ports forwarded. Does this look normal to you? Any chance whatever activity this is is causing the problem?

PS, the ping is now down to 12ms! Maybe an unrelated temporary glitch?

Re: Switched from BT and sync speed dropped significantly

Ok, I realise I'm largely talking to myself here but thought I'd post an update. I still have no idea where the barrage of activity on the firewall is coming from. The private IP they're hitting is my main computer but there's nothing on there soliciting any traffic on port 60951 and the hits continue when it's turned off.

On the subject of my speeds, my noise margin is at 17 dB when in the past it's been in single figures so it appears my line has been banded, probably due to some particularly bad period of my (unidentified) intermittent interference.